In enzymology, a 5-oxoprolinase (ATP-hydrolysing) () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are ATP, 5-oxo-<small>L</small>-proline, and H<sub>2</sub>O, whereas its 3 products are ADP, phosphate, and <small>L</small>-glutamate.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in cyclic amides. The systematic name of this enzyme class is 5-oxo-<small>L</small>-proline amidohydrolase (ATP-hydrolysing). Other names in common use include pyroglutamase (ATP-hydrolysing), oxoprolinase, pyroglutamase, 5-oxoprolinase, pyroglutamate hydrolase, pyroglutamic hydrolase, <small>L</small>-pyroglutamate hydrolase, 5-oxo-<small>L</small>-prolinase, and pyroglutamase. This enzyme participates in glutathione metabolism.